Measurements of correlation, height gain, and path antenna gain at 1046 megacycles on spaced antennas far beyond the radio horizon

Abstract

Studies made and reported by the National Bureau of Standards in 1953 on the correlation of 1046 Mc radio fields on spaced antennas at distances far beyond the radio horizon are supplemented by more recent measurements. Data taken from three vertically spaced dipole antennas for longer periods of time allow correlations of instantaneous fields to be determined for various fading rate conditions. Measurements were made on the National Bureau of Standards Cheyenne Mountain transmission path in Colorado and Kansas at a frequency of 1046 Mc, the receiving location being at an angular distance of 27 milliradians (for standard atmosphere), i.e. anoroximately 150 miles beyond the transmitter radio horizon. In addition to the correlation of instantaneous fields, the correlation of hourly median fields and the diurnal variation of the received signal are shown. Simultaneous measurements from a parabolic reflector antenna are used to indicate the loss in gain relative to the expected free space gain of a large aperture array.